Automatic change return apparatus

ABSTRACT

An improved automatic change return apparatus, particularly useful in cooperation with a liquid dispenser such as a gasoline pump type dispenser, wherein a verifier receives a monetary input and actuates a change calculator after verifying the genuineness of the monetary input. The change calculator includes a circuit selector having a plurality of conductive portions, and a contact movably engaging the circuit selector, the contact being moved in response to the flow of fluid through the liquid dispenser such that the contact contactingly engages predetermined conductive portions, the conductive portions being connected to various portions of a changer such that a portion of the changer is energized via the conductive portions in contact therewith to return the correct change.

United States Patent 1 1 Mitchell [111 3,747,732 July 24, 1973 [76] Inventor: Sammy C. Mitchell, 7205 NW. 8th,

Oklahoma City, Okla.

[22] Filed: Aug. 18, 1971 [21] Appl. No.: 172,743

[52] US. Cl. 194/1 M, 133/4, 194/13 [51] Int. Cl. G071 13/06 [58] Field of Search 194/1 M, l N, l D, 194/3, 5, 9, l3; 133/4 [56] References Cited UNITED STATES PATENTS 3,589,491 6/1971 De Crepy 194/5 3,186,531 6/1965 Adams 194/9 X 3,550,743 12/1970 Rothschild 194/13 AUTOMATIC CHANGE RETURN APPARATUS LIQUID l6 Maw/o FLOW caureauae L/OU/D PUMP SENSOR POWER SUP/ L Y 2 CHANGE Primary Examiner-Robert B. Reeves Assistant Examiner-Thomas E. Kocovsky Attorney-Dunlap, Laney, Hessin -& Dough erty [57] ABSTRACT An improved automatic change return apparatus, particularly useful in cooperation with a liquid dispenser such as a gasoline pump type dispenser, wherein a verifier receives a monetary input and actuates a change calculator after verifying the genuineness of the monetary input. The change calculator includes a circuit selector having a plurality of conductive portions, and a contact movably engaging the circuit selector, the con tact being moved in response to the flow of fluid through the liquid dispenser such that the contact contactingly engages predetermined conductive portions, the conductive portions being connected to various portions of a changer such that a portion of the changer is energized via the conductive portions in contact therewith to return the correct change.

17 Claims, 8 Drawing Figures ACTUA 7U? g w a SAMMY C. M/TC'HELL 3 Sheets-Sheet l Patented July 24, 1973 Qudk \SGQYE AUTOMATIC CHANGE RETURN APPARATUS BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates generally to change return apparatus and, more particularly, but not by way of limitation, to an automatic change return apparatus for use in cooperation with a liquid dispenser.

2. Brief Description of the Prior Art In the past there have been various devices constructed to return change to a customer based upon a particular monetary input. For example, there have been devices constructed to receive a l-dollar bill or a S-dollar bill, verify that the monetary input is genuine United States Currency, and dispense one dollar or five dollars worth of coins. More particularly, with respect to liquid dispensers, such as gasoline pump type dispensers, various attempts have been made in the past to construct an apparatus for receiving a particular input and dispensing a predetermined amount of liquid in response thereto, and there have also been some attempts to construct an apparatus for receiving a monetary input and returning the correct change to the customer. However, most of these prior attempts have utilized extremely complicated apparatus, which required major modifications to existing dispensing equipment prior to being utilized in cooperation therewith, and a substantial investment which limited the practicalutilization thereof.

SUMMARY OF THE INVENTION An object of the present invention is to provide an automatic change return apparatus for receiving a monetary input and returning the correct change to a customer in response to the customer's particular use.

Another object of the invention is to provide a change return apparatus for returning the correct change to a customer which is economical in construction and operation thereof.

One other object of the invention is to provide a change return apparatus for receiving a monetary input and returning the correct change to the customer in response to the amount of liquid dispensed by the customer through a liquid dispenser.

A further object of the invention is to provide a change return apparatus which can be quickly and easily installed for utilization with most existing liquid dispensers.

A yet further object of the invention is to provide an automatic change return apparatus for receiving monetary inputs of various denominations and returning the correct change to the customer in response to the amount of the liquid dispensed by the customer through a liquid dispenser.

Other objects and advantages of the invention will be evident from the following detailed description when read in conjunction with the accompanying drawings which illustrate a preferred embodiment thereof.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a partial schematic, partial diagrammatical view of the automatic change return apparatus of the present invention.

FIG. 2 is a typical cross sectional view of a portion of a change calculator utilized in the automatic change return apparatus of FIG. 1.

FIG. 3 is an elevational view of one of the circuit selectors and one of the switch supports of the change return apparatus of FIG. 1.

FIG. 4 is an elevational view, similar to FIG. 3, but showing one other circuit selector and one other. switch support of the change return apparatus of FIG. 1.

FIG. 5 is an elevational view of the cam utilized in cooperation with the circuit selector and the switch support of FIG. 3.

FIG. 6 is an elevational view of the cam utilized in cooperation with the circuit selector and the switch support of FIG. 4.

FIG. 7. is an enlarged, cross sectional view showing the construction of a typical cam sllot, illustrative of the construction of the cam slots formed in the cams of FIGS. 5 and 6.

FIG. 8 is a partial schematic, partial diagrammatical view showing some of the components of the change return apparatus of FIG. 1, in one particular change position thereof.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawings in general, and to FIG. 1 in particular, diagrammatically and schematically shown therein and designated by the general reference numeral 10 is an automatic change return apparatus constructed to be utilized in cooperation with a liquid dispenser 12 for receiving a monetary input and returning the difference between the monetary input and the price of the specific amount of liquid dispensed through the liquid dispenser 12 or, in other words, for automatically returning the correct change. The change return apparatus 10 is particularly constructed to be utilized in cooperation with a gasoline type pump dispenser in such a manner that a monetary input, such as one dollar or a 5-dollar bill for example, is received by the change return apparatus 10 and the gasoline pump type dispenser is actuated to a pump position wherein the customer can dispense gasoline through the liquid flow controller (the nozzle) after the monetary input has been verified. After the customer has dispensed the desired amount of gasoline, the customer will deactuate the gasoline pump type dispenser, and the automatic change return apparatus 10 will automatically return the correct change to the customer, in a manner which will be described in greater detail below.

The liquid dispenser 12 generally includes a liquid pump motor 14 which is drivingly connected to a liquid pump 16, the liquid pump 16 pumping the liquid from a reservoir through a liquid flow controller 18 via a conduit 20, connecting the liquid pump 16 to the liquid flow controller 18, in a driven position of the liquid pump 16, that is a position wherein the liquid pump motor 14 is connected to the power supply and in a dispensing position of the liquid flow controller 18. In one form, the liquid flow controller 18 can be a handoperated type valve which is connected to the liquid.

particularly, connected to the power supply 22 via a motor starter or the like (not shown), rather than being directly connected thereto. A pump positioning network 28 is interposed generally between liquid pump motor 14 and the power supply 22 and, more particularly, the pump positioning network 28 is interposed in series in the conductor 26 to establish and interrupt the electrical continuity therebetween for positioning the liquid dispenser 12 in a pump position and a potential pump position, in a manner which will be described in greater detail below.

A flow transmitter 30 is hydraulically interposed in the conduit 20, generally between the liquid pump 16 and the liquid flow controller 18, and a portion of the flow transmitter 30 is connected to the power supply 22 via a pair of conductors 32 and 34, the conductor 32 being connected to the conductor 26 and the conductor 34 being connected to the conductor 24. The flow transmitter 30 is, more particularly, constructed to sense the flow of liquid through the conduit 20 or, in other words, to sense the flow of liquid being dispensed via the liquid flow controller 18, and to provide an output signal via a pair of conductors 36 and 38, the output signal being proportional to the rate of flow of the liquid. Flow transmitters constructed to operate in a manner similar to that described above with respect to the flow transmitter 30 are well known in the art, and a detailed description of the construction and operation thereof is not required herein.

The automatic change return apparatus includes, a verifier 44 which is connected to the power supply 22 via a pair of conductors 46 and 48. The verifier 44 is connected to a solenoid type actuator 50 of a first change calculator 52 via a pair of conductors 54 and 56, and is connected to a solenoid type actuator 58 of asecond change calculator 60 via a pair of conductors 62 and 64. The verifier 44 is constructed to receive the monetary input and to verify the genuineness of such monetary input, the verifier 44 providing electrical continuity between the power supply 22 and the solenoid actuator 50 or 58 after verifying the genuineness of the monetary input. More particularly, and in a preferred form, the verifier 44 is constructed to receive and verify a l-dollar bill or a S-dollar bill; the first change calculator 52 is constructed to determine the change to be returned generally between 5 cents and 95 cents in 5-cent increments; and the second change calculator 60 is constructed to determine the change to be returned generally between 1 dollar and 5 dollars in l-dollar increments. Verifiers constructed to receive United States currency in denominations of 1 dollar and 5 dollars and to verify the genuineness of such currency are well know in the art, and may be of the type manufactured by MICRO MAGNETIC INDUSTRIES of PALO ALTO, CALIF., for example, the construction and the operation of the first change calculator 52 and the second change calculator 60 to be described in greater detail below.

The first change calculator 52 and the second change calculator 60 are each constructed to transmit a change signal indicative of the correct monetary amount of change to be returned in a change position of the automatic change return apparatus 10. More particularly, and ina preferred form, the change signal from the first change calculator 52 is indicative of the change to be returned from 0 to 1 dollar in S-cent increments, and the change signal from the second change calculator 60 is indicative of the change to be returned from 0 to 5 dollars in l-dollar increments, the change signals from the first change calculator 52 and the second change calculator 60 combining to provide a cummulative change signal indicative of the change to be returned from O to five dollars in S-cent increments, in a manner to be described in greater detail below.

A changer 66 is connected to the first change calculator 52 and to the second change calculator 60 to receive the change signals therefrom. The changer 66, in one form, has storage areas for storing various monetary change pieces having denominations of 5 cents, 10 cents, 25 cents and 50 cents, for example, and a plurality of change solenoids, each change solenoid being connected to one of the various storage areas for releasing one of the change pieces stored therein, in an actuated position of the particular change solenoid. Thus, the change signals, more particularly, selectively actuate the change solenoids to return the correct amount of change via the changer 66. Changers constructed to receive change signals and to dispense or return change in response thereto are well known in the art, and may be of the type manufactured by STAN- DARD CHANGE-MAKERS of INDIANAPOLIS, IN- DIANA, for example. It should also be noted that, in a preferred form, the various components and the interconnections therebetween of the changer 66 and the verifier 44 are supported in a common housing, diagrammatically indicated in FIG. 1 by the general reference numeral 70, thereby comprising a unitary assembly which, in one operational embodiment, is supported near the gasoline type pump dispenser so that the customer or operator will have access thereto, during the operation of automatic change return apparatus 10.

A dry air supply 72 is connected to the verifierchanger housing via a conduit 74, and a control sensor 76 is interposed in the conduit 74 generally between the housing 70 and the dry air supply 72. The control sensor 76 is connected to a switch 78 having one switch position, as shown in FIG. 1, wherein the power supply 22 is connected to the verifier 44 via the conductor 48 through the switch 78, and one other switch position wherein the electrical continuity between the power supply 22 and the verifier 44 is interrupted and an out-of-order lamp indicator 80 is connected to the power supply 22. A cut-off switch 82 is interposed in the conductor 46, generally between the power supply 22 and the verifier 44, the cut-off switch 82 being hand-operated, in a preferred form, and interrupting the electrical continuity between the verifier 44 and the power supply 22 in a disconnect position of the change return apparatus 10.

The dry air supply 72 provides dry, filtered air to the verifier-changer housing, the dry air having a pressure level slightly higher than the atmospheric pressure generally surrounding the outside of the housing 70. The dry air inside the housing 70 is thus of a sufficient pressure level to substantially assure than any gasoline fumes existing near the housing 70 will be prevented from entering the housing 70, thereby substantially reducing the opportunity of a tire or the like being ignited within the housing 70, which is'particularly desirable when the change return apparatus 10 is being utilized in cooperation with a gasoline type pump dispenser.

It will be apparent from the foregoing to those skilled in the art, that, during the normal operation of the change return apparatus 10, the switch 82 is closed and the switch 78 is positioned, as shown in FIG. 1, to establish electrical continuity between the power supply 22 and the verifier 44 via the conductors 46 and 48. The control sensor 76 is constructed to sense the dry air being supplied by the air supply 72 to the housing 70 via the conduit 74, and to actuate the switch 78 to an out-of-order position wherein the electrical continuity is interrupted between the verifier 44 and the power supply 22, thereby de-energizing the verifier 44, and wherein electrical continuity is established between the lamp indicator 80 and the power supply 22, thereby lighting the lamp indicator 80 to provide a visual indication that the verifier 44 is de-energized and that a malfunction has been experienced in the dry air supply 72 or the conduit 74.

As diagrammatically shown in FIG. 1, the first change calculator 52 also includes a first drive motor 84 which is gearingly connected to a driver 86 via a meshing drive gear 88. The driver 86 is linkingly connected to a cam 90 via a pair of extension arms 92 and 94; the extension arm 92 being connected to the cam 90 and extending a distance generally perpendicularly therefrom, and the extension arm 94 being connected to the driver 86 and extending a distance generally perpenducularly therefromsThe cam 90 and. the driver 96 are each rotatingly supported within the first change calculator 52, and the extension arms 92 and 94 are each disposed such that the extension arm 94 of the driver 86 will contactingly engage the extension arm 92 of the cam 90 to rotatingly drive the cam 90, during one aspect of the operation of the first change calculator 52, as will be described in greater detail below.

A circuit selector 96 is secured in a stationary position within the first change calculator 52, the cam 90 being interposed generally between the driver 86 and the circuit selector 96. A contact 98 is securely connected to the cam 90, generally near the outer periphery thereof, a portion of the contact 98 extending from the cam 90 to a position wherein one end portion thereof movably contacts a portion of the circuit selector 96 or, more particularly, movably contacts various conductive portions of the circuit selector 96. The various conductive portions (to be described in greater detail below) of the circuit selector 96 are each connected to the changer 66, and the contact 98 is connected to the power supply 22, in one position of the change return apparatus 10, such that the contacting engagement between particular conductive portions of the circuit selector 96 and the contact 98 determines the particular change signal to be transmitted from the first change calculator 52, in a manner to be described in greater detail below.

The second change calculator 60 is constructed similar to the first change calculator 52, and includes a second drive motor 100 which is gearingly connected to a driver 102 via a meshing gear 104. The driver 102 is linkingly connected to a cam 106 via a pair of extension arms 108 and 110; the extension arm 108 being connected to the cam 106 and extending a distance generally perpendicularly therefrom. The cam 106 and the driver 102 are each rotatingly supported within the second change calculator 60, and the extension arms I08 and 110 are each disposed such that the extension arm 110 of the driver 102 will contactingly engage the extension arm 108 of the cam 106, during one aspect of the operation of the second change calculator 60, as will be described in greater detail below.

A circuit selector 112 is secured in a stationary position within the second change calculator 60, the cam 106 being interposed generally between the driver 102 and the circuit selector 112. A contact 114 is securely connected to the cam 106, generally near the outer periphery thereof, a portion of the contact 114 extending from the cam 106 to a position wherein one end portion thereof movably contacts a portion of the circuit selector 112 or, more particularly, movably contacts various conductive portions of the circuit selector 112. The various conductive portions (to be described in greater detail below) of the circuit selector 112 are each connected to the changer 66, and the contact 114 is connected to the power supply 22, in one position of the change return apparatus 10, such that the contacting engagement between particular conductive portions of the circuit selector 112 and the contact 114 determines the particular change signal transmitted from the second change calculator 60, in a manner to be described in greater detail below.

A pump switch assembly is rotatably supported such that the pump switch assembly 120 can be rotated in an actuated direction 122 to a pump position, as shown in FIG. 1, and in a deactuated direction 124 to an of or a change position. Four mercury type switches 126, 128, and 132 are supported on the pump switch assembly, the mercury switches 126, 128, 130 and 132 being rotated to a pump position and a change position as the pump switch assembly 120 is rotated in an actuated direction 122 and a deactuated direction 124. In one operational embodiment, and, in a preferred form, the pump switch assembly 120 is secured to the actuating lever of a gasoline pump type dispenser, the actuating lever being that lever which the operator must turn to position the gasoline pump type dispenser in a pump position or, in other words, a position wherein gasoline is delivered through the nozzle type liquid flow controller when actuated. However, in any event, the pump switch assembly 120 is connected to the automatic change return apparatus 10 such that the mercury switches 126, 128, 130 and 132 can be positioned in a pump position and a change position, for reasons and in a manner to be described i greater detail below.

The mercury switch 126 has three terminals 134, 136 and 138, and is positioned on the pump switch assembly 120 such that, in a pump position (shown in FIG. 1), electrical continuity is established therethrough between the terminals 134 and 138, and such that, electrical continuity is established therethrough between the terminals 134 and 136, in a change position of the pump switch assembly 120. The mercury switch 128 has four terminals 140, 142, 144 and 146, and is positioned on the pump switch assembly 120 such that, in a pump position, electrical continuity is established therethrough between the terminals 144 and 146, and electrical continuity is established therethrough between the terminals and 142, in a change position" of thepump switch assembly 120. The mercury switch 130 has three terminals 150, 152 and 154, and is positioned on the pump switch assembly 120 such that, in a pump position, electrical continuity is established therethrough between the terminals and 154, and electrical continuity is established therethrough between the terminals 150 and 152, in a change position of the pump switch assembly 120. The mercury switch 132 has two terminals 158 and 160, and is positioned on the pump switch assembly 120 such that, in the pump position, electrical continuity between the terminals 158 and 160 is interrupted, and electrical continuity is established between the terminals 158 and 160, in the change position of the pump switch assembly 120.

The change return apparatus also includes one other mercury type switch 162 which is supported on a switch support 164. The switch support 164 is connected to a switch actuator 166, the switch actuator 166 rotating the switch 162 to an actuated status wherein electrical continuity is established between a pair of terminals 168 and 169 of the switch 162, and to a deactuated status, as shown in FIG. 1, wherein the electrical continuity is interrupted between the terminals 168 and 169. In one form, the switch 162 is positioned in the changer 66 such that the returning change therefrom actuates the switch actuator 166 via an interconnecting trigger or lever arm or the like; however, in any event, the actuator 166 is constructed to move the switch 162 to an actuated status after the correct change has been returned to the customer, for reasons which will be made more apparent below.

The pump positioning network 28, mentioned before, includes three switches 170, 172 and 174, each switch being connected to the conductor 26 such that electrical continuity is established between the liquid pump motor 14 and the power supply 22 in the closed position of any one of the switches 170, 172 and 174. A circuit breaker 176 is interposed in the conductor 26, generally between the switch 170 and the switch 172, the circuit breaker 176 interrupting the electrical continuity between the liquid pump motor 14 and the power supply 22 in an open position thereof, and in an opened or a closed position of the switches 172 and 174. However in a closed position of the switch 170, electrical continuity is established between the liquid pump motor 14 and the power supply 22, in an opened or a closed position of the circuit breaker 176. The switch 170 is, in a preferred form, a hand-operated type switch and is positioned to bypass the switches 172 and 174 and the circuit breaker 176 in a closed position thereof, the switch 170 being'positioned such that the liquid dispenser 12 can be operated independent of the first change calculator 52 and the second change calculator 60. The switches 172 and 174 are positioned in the first change calculator 52 and the second change calculator 60, respectively, each switch 172 and 174 being automatically actuated by one of the change calculators 52 and 60, in a manner to be described in greater detail below.

A resistor 178 is interposed in series in the conductor 26, generally between the liquid pump motor 14 and the power supply 22, the resistor 178 being sized to reduce the speed of the first drive motor 84 and the second drive motor 100 when electrically connected in the conductor 26. A switch 180 and a switch 182 are each connected in parallel with the resistor 178 such that, in a closed position of the switch 180 or the switch 182, the resistor 178 is bypassed or, in other words, not electrically connected in the conductor 126. The switch 180 is positioned in the first change calculator 52 and the switch 182 is positioned in the second change calculator 60, each switch 180 and 182 being automatically actuated by one of the change calculators 52 and 60, in a manner to be described in greater detail below. The conductor 26 is connected to the terminal 136 of the mercury switch 126 via apair of conductors 186 and 188, the conductor 186 being connected to the conductor 26 generally between the circuit breaker 176 and the switch 170, and the conductor 188 connecting the terminal 136 of the switch 126 to the power supply 22. A fuse 190 is interposed in the conductor 188, generally between the connection between the conductors 186 and 188 and the power supply 22.

A liquid price change network 192 is interposed in the conductor 36, the conductor 36 being connected to a conductor 194 and the conductors 36 and 194 connecting the flow transmitter 30 to the first drive motor 84. The liquid price change network 192 includes a variable resistor 196, a resistor 198 and another variable resistor 200, the resistors 196, 198 and 200 each being interposed in series in the conductor 36. In a preferred form, the variable resistor 196, more particularly, is comprised of a decade type resistor box wherein various resistance values are selected by turning a knob, for example, and the variable resistor 200 is, more particularly, a pot-type variable resistor.

The liquid price change network 192 is thus inter posed generally between the first drive motor 84 and the flow transmitter 30, and the rotational, driving speed of the first drive motor 84 is, therefore, responsive to the resistance setting of the liquid price network 192. In this manner, should the price per gallon of the liquid be changed for any reason, the automatic change return apparatus 10 can be quickly and easily modified so that the first change calculator 52 determines the correct change to be returned in accordance with various, predetermined liquid price changes. The resistor 200 is, in a preferred form, utilized for fine calibration adjustments between the flow transmitter 30 and the first change calculator 52, the variable resistor 196 being utilized for liquid price change correlation.

A normally closed switch 202 is interposed in the conductor 38 generally between the flow transmitter 30 and the mercury switch 126, the conductor 38 being connected to the terminal 138 of the switch 126. The switch 202 is, in a preferred form, a hand-operated type of switch which is connected to the flow transmitter 30 such that the automatic change return apparatus 10 can be disconnected from the liquid dispenser 12.

The power supply 22 is connected to the conductor 36, generally between the liquid price control network 192 and the first drive motor 84 or, more particularly, the connection between the conductors 36 and 194, via a conductor 204. A switch 206 and a resistor 208 are interposed in series in the conductor 204, a switch 210 being connected in parallel with the resistor 208 to bypass the resistor 208 in a closed position of the switch 210. A pair of switches 212 and 214 are connected in series, and the switches 212 and 214 are connected in parallel with the switch 206 such that, in a closed position of the switches 212 and 214, the switch 206 is bypassed. The switches 206, 210 and 212 are eachdisposed within the first change calculator 52 to be automatically actuated thereby during the operation thereof, and the switch 214 is disposed within the second change calculator 60 to be automatically actuated thereby during the operation thereof, for reasons and in a manner which will be made more apparent below.

A conductor 216 is connected to the conductor 204, generally between the switch 206 and the resistor 208.

The conductor 216 connects the conductor. 204. with the terminal 140 of the mercury switch 128.

The changer 66 is connected to each of the conductive portions of the circuit selector 96 of the first change calculator 52 via a cable 220. The terminal 168.

of the mercury switch 162 is connected to the conductor 204, generally between the switch 206. andthe connection of the conductors 204 and 216,.via a conductor 222, and the terminal 169 of the. mercury switch 162 is connected to the changer 66 via a conductor 224,,the mercury switch 162 being connected to the changer 66 to create an. electrical short about the solenoids therein, during one aspect of the operation of the automatic change return apparatus 10.

The contact 98 of the first change calculator 52 is connected to the terminal 142 of the mercury switch 128 via a conductor 226, and the contact 114 of the. second change calculator 60 is connected to a conductor 228 via a conductor 230. The conductor 228 is connected to the power supply 22and to a conductor 232, thereby connecting the contact 114 to the power sup ply 22. v

A resistor 234 is interposed in the conductor 228 and a switch 236 is connected in parallel with the resistor 234 to bypass the resistor 234 in a closed position of theswitch 236. A switch 238 is interposed in the conductor 228, generally between the connection of the conductors 228 and 230 and the connection of the conductors 228 and 232. The switches 236 and 238 are each supported within the second change calculator 60 and actuated thereby during the operation thereof, in a manner to be described in greater detail below.

The first drive motor 84 is connected to the terminal 134 of the mercury switch 126 via a conductor240 and a fuse 242 is interposed in the conductor 240. A conductor 244 is connected to the conductor 240, generally between the first drive motor 84 and the mercury switch 126, the conductor 244 also being connected to drive motor 100 is also connected to the terminal 150 via a conductor 250. The conductor 232 is also connected to a conductor 252, the conductor 252 being connected to the power supply 22 through a fuse 254 and to the terminal 152 of the mercury switch 130.

The terminal 146 of the mercury switch 128 is connected to the conductor 36, generally between the connection of the conductors 36 and 204 and the connection of the conductors 36 and 194. The terminal144of the mercury switch 128 is connected to the conductor 232, generally between the connection of the conductors 228 and 232 and the lamp indicator 248, via a conductor 256.

A switch 258, a variable resistor 260 and a variable resistor 262 are interposed in the conductor 256 generally between the second drive motor 100 and the mercury switch 128, the variable resistor 262 being, in a preferred form, a pot-type variable resistor. The switch 258 is, in a preferred form, disposed in the second change calculator 60 and automatically actuated thereby, in. amanner to be described in greater detail.

below.

The changer 66 is connected to 'theconductiveportions of the circuit selector 112 of the second change calculator 60 via a conductor 264.. A conductor 268s conductor 270 being connected to the conductor 26 generally between the circuit breaker 176 and the switch 172. A fuse 272 is interposed in the conductor 270, as shown in FIG. 1.

As mentioned before, the first change calculator 52 and the second change calculator 60 are each constructed in a similar manner, a preferred construction of each being partially shown in FllG. 2. More particularly, shown in FIG. 2 is a preferred construction of'the drive gear 86 or 102, the cam 90 or 106, and the circuit selector 96 or 112 showing the assembly of the components or; a shaft 300 generally between a front support plate 302 and a rear support plate .304. One end of the shaft 300 is threadingly secured .in the front support plate 302 and the opposite end thereof extends through the rear support plate 304 and is secured therethrough via a nut 306. The shaft 300 extends through an opening 308 formed in a central portion. of the drive gear 86 or 102, through an opening 310 formed in a central portion of the cam 90 or 106 and through an opening 312 formed through a central portion of a switch support 314 or 316, the switch support 314 or 316 being secured in a central opening 318 formed through the circuit selector 96 or 112. It should be noted that the double numeral designations utilized in FIG. 2 to designate particular components, denote a common, similar assembly of those components, and has been utilized for the purpose of clarity.

The switch support 314 and 316 is constructed to provide a support structure for some of the switches (not shown in FIG. 2) of the automatic change return apparatus 10, and to position those switches to contactingly engage a cam surface 320 of the cam 90 or 106, the cam surface 320 being shaped to selectively actuate the switches supported on switch support 314 or 316 during the operation of the automatic change return apparatus 10. It should be noted that the switches supported on the switch support 314 or 316 could be supported on the circuit selector 96 or 112, thereby eliminating the necessity of a separate component, the switch support 314 or 316,,in one form of the invention; however, the switch support 314 or 316 is utilized in a preferred form for calibration purposes and for economy of manufacture.

The switch support 314 is, more particularly, secured to the circuit selector 96 of the first change. calculator 52, and the switch support 316 is, more particularly, secured to the circuit selector 112 of the second change calculator 60. The circuit selector 96 or 112 is secured in a stationary position to the front support plate 302 via a plurality of clips 322, the clips 322 being spaced about the outer periphery of the circuit selector 96 or 112 and retainingly engaging a portion thereof. The switch support 314 or 316 has a pair of elongated, arcuately shaped apertures 324 and 326, a screw328 being disposed through each aperture 324 and 326 and threadingly engaging the front support plate 302 to adjustingly and securely position the switch support 314 or 316 to the front support plate 302.

A cylindrically shaped conductive spacer 330 having an opening 332 extending therethrough is disposed generally between the circuit selector 96 or 112 and the cam 90 or 106. More particularly, one end of the conductive spacer 330 is disposed through the opening 312 in the switch support 314 or 316, the end of the conductive spacer 330 abutting the front support plate 302. The end of the conductive spacer 330, opposite the end thereof disposed through the switch support 314 or 316, abuts and slidingly contacts a bushing 334 which is secured to the cam surface 320 of the cam 90 or 106, generally about the opening 310 therethrough.

As shown in FIG. 2, a portion of the shaft 300, more particularly, extends through the bushing 334 and through the conductive spacer 330. The conductor 226 or 230 is embedded in the front support plate 302 and connected to a portion of the conductive spacer 330. A conductor 336 is connected to the bushing 334 and to the contact 98 or 114. The conductive spacer 330 and the bushing 334 are each constructed of an electrically conductive material, and the conductor 226 or 230 is thus connected to the contact 98 or 114 via the conductive spacer 330, the bushing 334 and the conductor 336. The conductive spacer 330 maintains a predetermined spacing between the cam 90 or 106 and circuit selector 96 or 112 to maintain the contact 98 or 114 in proper, contacting engagement with the circuit selector 96 or 112, and yet allow the cam 90 or 106 to be rotated relative to the circuit selector 96 or 112 while providing an electrical path therebetween.

A spacer 338 is interposed about a portion of the shaft 300, generally between the driver 86 or 102 and the cam 90 or 106, one end of the spacer 338 contacting the cam 90 or 106 and the opposite end of the spacer 338 contacting the driver 86 or 102. The spacer 338 maintains a predetermined distance between the driver 86 or 102 and the cam 90 or 106 to assure the proper orientation thereof and to assure proper, predetermined contacting engagement between the extension arm 92 or 108 and the extension arm 94 or 110 during the operation of the automatic change return apparatus 10.

A bias spring 340 is disposed about a portion of the shaft 300 and interposed generally between the rear support plate 304 and the driver 86 or 102. The bias spring 340 engages the driver 86 or 102 to biasingly move the driver 86 or 102 generally toward the front support plate 302 and into an assembled position.

Thus, the driver 86 or 102, the cam 90 or 106, the circuit selector 96 or 112, and the switch support 314 or 316 are secured in an assembled position, generally between the front support plate 302 and the rear support plate 304, the front support plate 302 and the rear support plate 304 being secured in an assembled position by a plurality of interconnecting bolts, for example. The driver 86 or 102 and the cam 90 or 106 are each, more particularly, rotatingly supported on a portion of the shaft 300, and the circuit selector 96 or 112 and the switch support 314 and 316 are each supported in a stationary position about the shaft 300, during one aspect of the operation of the change return apparatus 10.

A preferred embodiment of the circuit selector 96 and the switch support 314 of the first change calculator 52 is shown in FIG. 3. The circuit selector 96 is generally circularly shaped, and has a plurality of conductive portions 346 spaced thereabout generally near the outer periphery thereof (only some of the conductive portions 346 being designated in FIG. 3 for the purpose of clarity). As mentioned before, the circuit selector 96 is, in a preferred form, constructed to provide a change signal determinative of the change to be returned generally between 0 and one dollar in 5 cent increments. Thus, each conductive portion 346 is spaced about the circuit selector 96 to be contactingly engaged by the contact 98 after the cam has been driven a predetermined number of degrees indicating that an additional 5 cents worth of liquid has been dispensed via the liquid dispenser 12. The cam 90 and the circuit selector 96 are initially positioned and calibrated in an assembled position, as shown in FIG. 2, wherein the contact 98 engages a nonconductive portion of the circuit selector 96 generally along an initial or starting position 348.

Each of the conductive portions 346 are connected to predetermined portions of the changer 66 via a conductor 350, only a few of the conductors 350 being diagrammatically shown in FIG. 3 for the purpose of clarity. The conductors 350 form the cable 220, as shown in FIGS. 1 and 3.

The switch support 314 is secured in the opening 318 of the circuit selector 96, and the switches secured thereto are generally positioned along a radius through the starting position 348, as shown in FIG. 3. More particularly, the switches 172, 212, 206, 210 and are secured to the switch support 314.

A preferred embodiment of the circuit selector 112 and the switch support 316 of the second change calculator 60 is shown in FIG. 4. The circuit selector 112 is generally circularly shaped and has a plurality of conductive portions 354 spaced thereabout generally near the outer periphery thereof. The circuit selector 112 is, more particularly, constructed to provide a change signal determinative of the change to be returned generally between 0 and 5 dollars in l-dollar increments. Thus, each conductive portion is spaced about the circuit selector 112 to be contactingly engaged by the contact 114 after the cam 106 has been driven a predetermined number of degrees indicating that an additional l dollars worth of liquid has been dispensed via the liquid dispenser 12. The cam 106 and the circuit selector 112 are initially positioned and calibrated in an assembled position, as shown in FIG. 2, wherein the contact 114 engages a non-conductive portion of the circuit selector 1 12 at an initial or starting position 356. The conductive portions 354 are interconnected by conductors 358, and the conductor 264, connecting the circuit selector 112 with the changer 66 is, more particularly, connected to the last conductive portion 354 contacted by the contact 114 during one complete revolution of the cam 106.

The switch support 316 is secured in the opening 318 of the circuit selector 112, and the switches secured thereto are generally aligned along a radius through the starting position 356. More particularly, the switches 258, 174, 238, 214, 236 and 182 are secured to the switch support 316.

The cam 90 includes three cam slots 362, 364, and 366, and the cam 106 includes three cam slots 368, 370 and 372, as shown in FIGS. 5 and 6. Each cam slot 362, 364, 366, 368, 370 and 372 is formed in a portion of the cam surface 320 of one of the earns 90 or 106, a detailed view of a typical cam slot being shown in cross section in FIG. 7.

As shown in FIG. 7, each cam slot is countersunk or depressed in the cam surface 320, and has one wall 376 extending generally perpendicular to the cam surface 320 and one inclined wall 378 formed on a generally 45 inclination with respect to the cam surface 320. Each cam slot is particulary sized to receive a switch arm 380 of one or more of the switches secured to the switch support 314 or 316, the inclined wall 378 providing a path for the switch arm 380 to travel generally out of the cam slot and into engagement with the cam surface 320, during the operation of the automatic change return apparatus 10.

The conductive spacer 330 is thus, more particularly, sized to space the cam surface 320 of the cam 90 or 106 a predetermined distance from the switch support 314 or 316 such that the switch arms 380 are disposed within the cam slot (FIG. 7) in one actuated position of the switches, and such that the switch arms 380 engage the cam surface 320 in one other actuated position of the switches. Since the circuit selector 96 or 112 and the switch support 314 or 316 are each secured in a stationary position during the operation of the change return apparatus 10, the cam 90 or 106, more particularly, is drivingly rotated by the driver 86 or 102 to position the various cam slots in a switch arm receiving position with respect to predetermined switches and at predetermined cycle times, that is to position the various cam slots with respect to the switch arms 380 such that the switch arms 380 are disposed generally within the cam slots, as shown in FIG. 7. In other words, the switch arms 380 of the various switches secured on the switch support 314 or 316 engage the cam surface 320 of the cam 90 or 106, and are disengaged from the cam surface 320 via the cam slots at predetermined cycle times during the operation of the change return apparatus 10.

In a preferred form, as shown in FIGS. 2 and 5, the cam 90 is driven in a counterclockwise rotational direction 382 about a rotational axis 383, during the operation of the change return apparatus 10, the starting position 348 of the cam 90 intersecting the rotational axis 383 and extending generally radially therefrom. The cam slot 362 is spaced a radial distance 384 from the rotational axis 383 of the cam 90, the cam slot 362 having a radial width 386 and extending from the starting position 348 an angular distance 388, in a generally counterclockwise direction. The cam slot 364 is spaced a radial distance 400 from the rotational axis 383 of the cam 90, the cam slot 364 having a radial width 402 and extending from the starting position 348 an angular distance 404 in a generally counterclockwise direction. The cam slot 366 is spaced a radial distance 406 from the rotational axis 383 of thecam 90, the cam slot 366 having a radial width 408 and extending from the starting position 348 an angular distance 410 in a generally counterclockwise direction.

More particularly, the radial distance 384 positions the cam slot 362 on the cam 90, and the cam 90 is positioned with respect to the switch support 314 such that the switch arms of the switches 172 and 212 are disposed within the cam slot 362 when the cam 90 is positioned at the starting position 348 thereof, the switches 172 and 212 being constructed to be opened in this position. The switch arms of the switches 172 and 211 will remain disposed within the cam slot 362 until the cam 90 has been rotated an angular distance corresponding to the angular width 388 of the cam slot 362, the switch arms of the switches 172 and 212 engaging the inclined wall 378 and being moved into contacting engagement with the cam surface 320 in this position of the cam 90. The switches 172 and 212 are constructed to be closed when the switch arms thereof are contactingly engaged by the cam surface 320 of the cam 90.

The radial distance 400 of the cam slot 364 positions the cam slot 364 on the cam 90, and the cam 90 is positioned with respect to the switch support 314 such that the switch arm of the switch 206 is disposed within the cam slot 364 when the cam 90 is positioned at the starting position 348 thereof, the switch 206 being constructed to be opened in this position. The switch arm of the switch 206 will remain disposed within the cam slot 364 until' the cam 90 has been rotated an angular distance corresponding to the angular width 404 of the cam slot 364, the switch arm of the switch 206 engaging the inclined wall 378 and being moved into contacting engagement with the cam surface 320 in this position of the cam 90. The switch 206 is closed when the switch arm thereof is contactingly engaged by the cam surface 320 of the cam 90.

The radial distance 406 of the cam slot 364 positions the cam slot 364 on the cam 90, and the cam 90 is positioned with respect to the switch support 314 such that the switch arms of the switches 180 and 210 are disposed within the cam slot 364 when the cam 90 has been rotated to a position an angular distance from the starting position 384, the angular distance corresponding to the angular width 410 of the cam slot 364. In this position, the switch arms of the switches 180 and 210 will remain within the cam slot 364 as the cam 90 is rotated through an angular distance corresponding to the angular width 410 of the cam slot .364, the switch arms of the switches 180 and 210 engaging the inclined wall 378 and being moved into contacting engagement with the cam surface 320 as the cam 90 is rotated to the starting position 348. The switches 180 and 210 are constructed to be closed when the switch arms thereof are contactingly engaged by the cam surface 320, and to be closed when the switch arms thereof are disposed within the cam slot 366.

The cam 106 is also rotated in a counterclockwise:rotational direction 382 about the rotational axis 383 via the driver 102, during the operation of the change re turn apparatus 10, the starting position 356 of the cam 106 intersecting the rotational axis 383 and extending radially therefrom. The cam slot 368 is spaced a radial distance 414 from the rotational axis 383 of the cam 106, the cam slot 368 having a radial width 416 and extending from the starting position. 356 an angular distance 418 in a generally counterclockwise direction. The cam slot 370 is spaced a radial distance 420 from the rotational axis 383 of the cam 106, the cam slot 370 having a radial width 422 and extending from the starting position 356 an angular distance 424 in a generally counterclockwise direction. The cam slot 372 is spaced a radial distance 428 from the rotational axis 383 of the cam 106, the cam slot 372 having a radial width 430 and extending from the starting position 356 an angular distance 432 in a generally clockwise direction.

The radial distance 414 of the cam slot 368 positions the cam slot 368 on the cam 106, and the cam 106 is positioned with respect to the switch arms of the switches 258 and 174 such that the switch arms thereof are disposed within the cam slot 368 when the cam 106 is positioned at the starting position 356, the switches 258 and 174 being constructed to be opened in this position. The switch arms of the switches 258 and 174 will remain disposed within the cam slot 368 until the cam 106 has been rotated an angular distance corresponding to the angular width 418 of the cam slot 368, the switch arms of the switches 258 and 174 engaging the inclined wall 378 and being moved into contacting engagement with the cam surface 320 in this position of the cam 106. The switches 258 and 174 are in the closed position when the switch arms thereof are contactingly engaged by the cam surface 320 of the cam 106.

The radial distance 420 of the cam slot 370 on the cam 106, and the cam 106 is positioned with respect to the switch arms of the switches 238 and 214 such that the switch arms thereof are disposed within the cam slot 370 when the cam 106 is positioned at the starting position 356, the switches 238 and 214 being constructed to be opened in this position. The switch arms of the switches 238 and 214 will remain disposed within the cam slot 370 until the cam 106 has been rotated an angular distance corresponding to the angular width 424 of the cam slot 370, the switch arms of the switches 238 and 214 engaging the inclined wall 378 and being moved into contacting engagement with the cam surface 320 in this position of the cam 106. The switches 238 and 214 are in the closed position when the switch arms thereof are contactingly engaged by the cam surface 320 of the cam 106.

The radial distance 428 of the cam slot 372 positions the cam slot 372 on the cam 106, and the cam 106 is positioned with respect to the switch support 314 such that the switch arms of the switches 236 and 182 are disposed within the cam slot 372 when the cam 106 has been rotated to a position an angular distance from the starting position 356, the angular distance corresponding to the angular width 432 of the cam slot 372. In this position, the switch arms of the switches 236 and 182 will drop into the cam slot 372, the switches 236 and 182 being constructed to be actuatingly opened when the switch arms thereof are disposed within the cam slot 372. The switch arms of the switches 236 and 182 will remain within the cam slot 372 as the cam 106 is rotated through an angular distance corresponding to the angular width 432 of the cam slot 372, the switch arms of the switches 236 and 182 engaging the inclined wall 378 and being moved into contacting engagement with the cam surface 320 as the cam 106 is rotated to the starting position 356. The switches 236 and 182 are constructed to be closed when the switch arms thereof are'contactingly engaged by the cam surface 320.

It should be noted that the switches 172 and 212, the switches 210 and 180, the switches 258 and 174, the switches 238 and 214, and the switches 236 and 182 could each be a double-pole, single throw type of micro-switch in lieu of the two switch combinations mentioned above and shown in the drawings. In this manner, the necessity of utilizing two separate switches, each of which must be securely mounted on the switch support 314 or 316, is eliminated, thereby reducing the cost of manufacture, the two separate switches being described and shown for the purpose of clarity of description.

The actuated position of the switches 172, 212, 206, 210, and 180 of the first change calculator 52 and the switches 258, 174, 238, 214, 236 and 182 of the second change calculator 60 as the earns and 106 are being driven in the counterclockwise direction can thus be summarized as follows:

Switch designation 258 174 238 214 Angular position of cam 106 1. Starting position 356 2. After rotation through angular distance 418 3. After rotation through angular distance 424 4. Angular distance 432 from starting position 356 opened opened opened opened opened opened closed closed closed closed closed closed closed closed closed closed closed closed closed closed closed closed closed closed Switch designation 172 210 Angular position of cam 90 1. Starting position 348 2. After rotation through angular distance 388 3. After rotation through angular distance 404 4. Angular distance 410 from starting position 348 opened opened opened opened opened closed closed opened closed closed closed closed closed closed closed closed closed closed opened opened In one form, as mentioned before, the cam 90, the circuit selector 96 and the switch support 314 are, more particularly, constructed to determine the correct change from 0 to 1 dollar in 5 cent increments; and the cam 106, the circuit selector 112 and the switch support 316 are, more particularly, constructed to determine the correct change from 0 to 5 dollars in 1 dollar increments. In this embodiment of the invention the following angular dimensions have been determined to provide satisfactory results, for example:

Angular distance Corresponding Degrees or width from the Starting Positions 388 15 404 30 410 15 418 10 424 l5 432 3 Referring again to the particular embodiment of the invention mentioned above, the first conductive portion 354 encountered moving in a counterclockwise direction from the starting position 356 of the circuit selector 316 is located 60 from the starting position 356. Each conductive portion 356 has an angular width of 12, and each conductive portion 356 is spaced 60 from the adjacent conductive portion 356, with the exception of the space between the last conductive portion 356 encountered moving in a counterclockwise direction and the first conductive portion 356, the last conductive portion 356 being spaced 72 from the starting position 356 in a counterclockwise direction 382.

OPERATION OF THE PREFERRED EMBODIMENT The automatic change return apparatus 10, described before, is constructed to receive a monetary input from a customer, verify that the monetary input is genuine, and to automatically return the correct change to the customer after the customer has dispensed a desired amount of the liquid. In one form, as mentioned before, the change return apparatus 10 is utilized in cooperation with a gasoline pump type dispenser, and the change return apparatus 10 is, more particularly, constructed to receive a S-dollar bill or a l-dollar bill from the customer, verify that the S-dollar bill or the l-dollar bill is genuine United States Currency, and automatically return the correct change to the customer after the customer has dispensed the desired amount of gasoline (the change being the difference between the monetary input, the -dollar bill or the l-dollar bill and the sales price per gallon of gasoline multiplied by the number of gallons of gasoline actually dispensed by the customer). Utilizing the change return apparatus of the present invention in a manner last-mentioned above, the first change calculator 52 is particularly constructed to calculate thechange between zero and 1 dollar, and the second change calculator 60 is particularly constructed to calculate the change between zero and 5 dollars, in a manner discussed above, the operation of the change return apparatus 10 being described below with respect to this particular application for the purpose of clarity.

Assuming a customer has inserted a l-dollar bill in the verifier 44, the verifier will scan the inserted monetary input and, upon determining the monetary input to be genuine United States Currency, the verifier 44 will close a circuit (not shown) connecting the power supply 22 to the solenoid actuator 50 via the conductors 46, 48, 54 and 56, thereby energizing the solenoid actuator 50. In the actuated position of the solenoid actuator 50, a portion of the solenoid actuator 50 will engage the extension arm 92 of the cam 90, causing the cam 90 to be rotated a predetermined number of degrees in a counterclockwise direction or, more particularly, causing the cam 90 to be rotated a number of degrees corresponding to the angular width 388 of the cam slot 362, thereby closing the switches 172 and 212 in a manner as described before.

The closing of the switch 172 provides electrical continuity between the liquid pump motor 14 and the power supply 22, thereby giving the liquid pump 16 potential power to operate. As briefly mentioned before,

the liquid dispenser 12 is constructed such that the liquid flow controller 18 cannot be actuated to dispense liquid therefrom until a lever arm (:not shown) has been properly positioned (rotated).

The operator will then rotate the lever arm, mentioned above, thereby rotating the pump switch assembly 120 in an actuated direction 122 and thus rotating the mercury switches 126, 128, 130 and 132 to the pump position, as shown in FIG. 1. In this position, the operator can dispense liquid from the liquid dispenser 12 via the liquid flow controller 1 8.

The liquid dispensed by the liquid dispenser l2 flows through the flow transmitter 30, the flow transmitter 30 providing an output flow signal via the conductors 36 and 38 proportional or responsive to the rate of the flow of liquid therethrough. The flow signal is transmitted through the liquid price change network 192, and is transmitted to the first drive motor 84 via the conductors 36 and 240 via the mercury switch 126. The voltage of the transmitted flow signal is thus controlled via the settings of the resistors 196, 198 and 200 of the liquid price change network 192, the voltage finally applied to the first drive motor 84 determining the output rotational speed thereof.

Since the output flow signal of the flow transmitter 30 is responsive to the rate of the flow of liquid through the liquid dispenser 12, the flow signal finally applied to the first drive motor 84 will be responsive to the rate of the flow of the liquid and the unit price thereof or, in other words, the price per gallon of the liquid as determined by the price control network. Thus, assuming that the variable resistor 196 has been set in accordance with the desired price of the liquid per unit of volume, the driver 86 will be rotatingly driven at a speed responsive to the price per unit of the liquid so that the cam 90 will rotate through one completecycle (360) as l dollars worth of the liquid is dispensed via the liquid dispenser 12, for example.

It is particularly important to note that the cam 90 was moved through the angular width 388 to initially actuate the change return apparatus 10 in an operational mode. Thus, if the cam surface were formed directly on the driver 86,, thereby eliminating the separate cam element and the interconnectingextension arms 92 and 94, the first drive motor 84 would drive the modified cam-driver through the angular width 388, and would then drive the modified cam-driver through one complete cycle (360) less the angular width 388 as l dollars worth of liquid is dispensed through the liquid dispenser 12. Thus, utilizing the separate units; the driver 86, the cam 90, and the interconnecting extension arms 92 and 94, the first drive motor 84 will drive the driver 86 through one complete cycle (360), thereby reducing the cost of manufacture (the additional circuitry, the mechanical actuators and devices necessary to actuate the change return apparatus 10 in the operational mode) while simultaneously providing a more accurate first change calculator 52. It should also be noted that the extension arms 108 and provide the driving interconnection between the driver 102 and the cam 106 of the second change cal culator- 60 for substantially the same reason as described above with respect to the first change calculator 52.

The driver 86 will rotatingly drive the cam 90, and, after the cam 90 has been rotated through the angular width 404, the switch 206 is closed. The switch 206 electrically connects what is sometimes referred to below as the override system" to the change return apparatus 10. It should be noted that the switch 206 is closed after the cam 90 has been driven through a predetermined number of degrees since, if the switch 206 were in the closed position at the beginning of the operational cycle, the first drive motor 84 would be connected to the power supply 22 via the switch 206 and the mercury switch 126. In this latter-mentioned event, the driver 86 and the cam 90 would be rotated even though the customer had not actuated the liquid flow controller 18.

Assuming the customer continues to dispense the liquid via the liquid flow controller 18, the cam 90 will continue to be drivingly rotated in a counterclockwise direction 382, the contact 98 continually contacting the circuit selector 96 as the cam 90 is being thus rotated. When the cam 90 has been rotated to a position generally within an angular width 410 from the starting position 348, the switches 180 and 210 are actuatingly opened via the cam slot 366. The opening of the switch 180 will electrically place the resistor 178 in the pump positioning network 28 to reduce the power applied to the liquid pump motor 14, thereby reducing the flow of liquid through the liquid dispenser 12 and, particularly, through the flow transmitter 30. In this manner, the output rotational speed of the first drive motor 84 will be reduced so that the rotational speed of the cam 90 is reduced as the cam 90 approaches the completion of the cycle (3600 or, more particularly, approaches the starting position 348.

When the cam 90 has been rotated one complete cycle and is repositioned at the starting position 348 thereof, the cam surface 320 and the cam slots 362 and 364 position the switches 172, 212, 206, 210 and 180 accordingly. In this position, the customer will have dispensed l dollars worth of liquid through the liquid dispenser 12, and the automatic change return apparatus 10 is positioned to receive additional monetary inputs thereto.

Referring to a portion of FIG. 8, and, more particularly, the diagrammatical showing of the circuit selector 96 and the contact 98 which is in contacting engagement with the first conductive portion 346 (only some of the conductive portions 346 being shown in FIG. 8 for the purpose of clarity), the cam 90 has been driven via the first drive motor 84 to a position indicating that the customer has dispensed one increment of the liquid. More particularly, assuming that the first change calculator 52 is constructed to determine change in S-cent increments, mentioned before, the position of the contact 98, as shown in FIG. 8, indicates that the cam 90 has been rotated through a predetermined number of degrees corresponding to the dispensing of cents worth of liquid through the liquid dispenser 12. If, in this position of the cam 90 and the contact 98, the liquid flow controller 18 is positioned on the liquid dispenser 12 or, more particularly, if the pump switch assembly 120 is rotated in a deactuated direction 124, the mercury switches I26, 128, 130 and 132 are moved to the change position, thereby indicating the customer has dispensed the desired amount of liquid (5 cent's worth).

In the change position of the automatic change return apparatus 10, the contact 98 is connected to the power supply 22 via the mercury switch 128 (the conductors 226, 216, and 204) and the switch 206. The first conductive portion 346 is connected to the changer 66, as shown in FIG. 8, via the cable 220 and through the circuit breaker 176, thereby connecting a portion of the changer 66 to the power supply 22.

The conductive portions 346 are connected to various predetermined solenoids in the changer 66, as mentioned before, and, therefore, the particular solenoids in the changer 66 connected to the particular conductive portions 346 of the circuit selector 96 in contacting engagement with the contact 98 when the change return apparatus 10 is moved to the change position will be energized and will return to the customer the change associated therewith, the power supply 22 thus energizing a particular portion of the changer 66 via the contacting engagement between the contact 348 and the particular conductive portion 346. Referring to the example shown in FIG. 8, the first conductive portion 346 is, more particularly, connected to two lO-cent solenoids, one 25-cent solenoid, and one SO-cent solenoid, and the changer 66 will thus dispense 95 cents in change, the correct change since the customer had dispensed 5 cents worth of liquid in this example, as mentioned before.

The dispensing of change from the first change calculator 52 will cause the actuator 166 to move the mercury switch 164 to the actuated position wherein electrical continuity is established between the contacts 168 and 169 thereof. In this position of the mercury switch 164, the conductor 224 is connected to the conductor 222, thereby establishing an electrical short circuit around the changer 66 to essentially disconnect the changer 66 from the power supply 22.

The fuse 272 has, in a preferred form, a higher amperage rating than the circuit breaker 176; therefore, the circuit breaker 176 will be moved to an opened position establishing an electrical discontinuity through the conductor 270, when the mercury switch 164 establishes the electrical short circuit, referred to above. The electrical discontinuity through the conductor 270 holds or maintains the solenoids in the changer 66 in a de-energized position or, in other words, disconnects the changer 66 from the power supply 22. Thus, the automatic change return apparatus 10 is positioned to prevent the returning of change to the customer during the operation of the override system or, in other words, will not dispense change to the customer each time the contact is established between the contact 98 and one of the conductive portions 346 of the cam 90, as the cam is rotated to the starting position 348. Further, since the liquid pump motor 14 is connected to the power supply 22 via the circuit breaker 176, the electrical discontinuity established by the circuit breaker 176 will also establish an electrical discontinuity between the liquid pump motor 14 and the power supply 22, thereby positioning the liquid dispenser 12 in a nonoperative mode wherein liquid cannot be pumped or dispensed therethrough.

In the change position of the automatic change return apparatus 10, the first drive motor 84 will remain in an operative mode or, in other words, the electrical continuity between the first drive motor 84 and the power supply 22 is maintained via the mercury switch 126 and the switch 206. The first drive motor 84 will, thus, continue to rotatingly drive the driver 86 and the cam 90 after the change has been dispensed via the changer 66, the cooperation between the various switches and the electrical position of the circuit breaker 176 each cooperating to functionally provide a portion of the override system mentioned above.

When the cam 90 has been rotated to a position within a predetermined angular distance from the starting position 348, the angular distance more particularly corresponding to the angular width 410, the switches 210 and 180 are opened via the engagement thereof with the cam slot 366. In this position of the switches 210 and 180, the resistors 208 and 178 are electrically connected to the control circuit of the automatic change return apparatus 10, thereby reducing the rotational speed of the first drive motor 84 prior to the instant when the cam 90 has been rotated to thestarting position 348. In this manner, the cam 90 is more accurately positioned in the starting position 348, and the various switch arms of the switches on the switch support 314 are more precisely positioned on the cam surface 320 or in the slots 362 and 364, as described before.

The cam 90 also has a lobe or protrusion 440 formed on a portion thereof, as shown in FIG. 5. The protrusion 440 is positioned on the cam 90 and the circuit breaker 176 is positioned with respect to the cam 90, such that the protrusion 440 contacts a portion of the circuit breaker 176 to reset the circuit breaker 176 or, more particularly, to re-establish electrical continuity therethrough immediately prior to the time when the cam 90 has been rotated back to the starting position 348.

fore. The first drive motor 84 is also connected to the power supply 22 and, therefore, the first drive motor 84 Referring particularly to the example, operational embodiment mentioned above, and further assuming, for example, if the customer inserts a S-dollar bill in the verifier 44, the verifier 44 will verify that the inserted S-doilar bill is genuine United States Currency and, after this verification, will establish electrical continuity between the power supply 22 and the solenoid actuator 58 of the second change calculator 60 via the conductors 62, 64, 46 and 48. In the energized position of the solenoid actuator 58, a portion thereof will contact a portion of the extension arm 108 of the cam 106 and move the cam 106 a predetermined number of degrees in a counterclockwise direction, in a manner similar to the solenoid actuator 50 and the extension arm 92 described above.

More particularly, the solenoid actuator 58 will move the cam 106 a predetermined number of degrees substantially corresponding to the angular width 418 of the cam slot 368. In this position of the cam 106, a portion of the switches 174 and 258 will be moved generally out of the cam slot 368 and be actuatingly engaged via the cam surface 320 of the cam 106, thereby closing the switches 174 and 258. The closing of the switch 258 establishes electrical continuity between the second drive motor 100 and the power supply 22 via the mercury switches 128 and 130, the price control network 192, the flow transmitter and the variable resistors 260 and 262. It should be noted that the switch 258 is positioned to maintain electrical discontinuity between the power supply 22 and the second drive motor 100 during the operation of the change return apparatus 10 after the customer has inserted a l-dollar bill. The closing of the switch 174 establishes electrical continuity between the liquid pump motor 14 and the power supply 22, the switch 174 electrically bypassing the switch 172 due to the parallel interconnection therebetween.

After the customer has rotated the pump switch assembly 120 in the actuating direction 122, the mercury switches 126, 128, 130 and 132 are positioned in the pump position, as shown in FIG. 1, and as described beand the second drive motor 100 are each positioned in an operative mode, the first drive motor 84 and the second drive motor 100 each driving the cam and the driver connected thereto, during the operation of the change return apparatus 10. It should be noted, however, that the first drive motor 84 is connected to drive the driver 86 and the cam 90 at a rotational speed generally five times faster with respect to the rotational speed established via the interconnection between the second drive motor and the driver 102 and the cam 106, since the cam 90 will be rotated through five cycles (360 each) as the cam 106 is rotated through one complete cycle (360).

After the cam 106 has been rotated through an angular distance corresponding to the angular width 424 of the cam slot 370, the switch arms of the switches 238 and 214 will be actuatingly engaged via the cam surface 320 of the cam 106, thereby actuating what is sometimes referred to below as the override system of the second change calculator 60. Thus, when the customer inserts a S-dollar bill and after verification thereof, the first change calculator 52 and the second change calculator 60 are each positioned to cooperate in determining the correct change to be returned to the customer after the customer has dispensed the desired amount of liquid.

Since the cam 90 will be rotated through five complete cycles as the cam 106 is rotated through one complete cycle, the switch 180 will be actuatingly opened each time the cam 90 approaches a position within an angular width 410 from the starting position 348 thereof, thereby attempting to reduce the rotational speed of the first drive motor 84,. in a manner as described before. However, since the switch 182 is in electrical parallel with the switch 180, the rotational speed of the first drive motor 84 will not be reduced due to the overriding function of the switch 182 which is controlled via the cam 106 of the second change calculator 60. After the cam 106 has been rotated to a position within an angular distance corresponding with the angular width 432, the switches 236 and 182 will be actuatingly opened, thereby electrically connecting the resistors 178 and 234 in the control circuit of the automatic change return apparatus 10 to reduce the rotational speed of the first drive motor 84 and the second drive motor 100, for substantially the same purposes as mentioned before.

For example, it will be assumed that the customer has inserted a S-dollar bill into the verifier 44 and has dispensed $2.95 worth of liquid through the liquid dispenser 12. After the customer has actuated the pump switch assembly in the deactuated direction 124, the mercury switches 126, 128, and 132 will be positioned in the "change before.

In this position of the change return apparatus 10, the contact 98 will be positioned in contacting engagement with the first conductive portion 346, thereby actuating the solenoids in the changer 66 to return 95 cents in change to the customer, in a manner as described before and as shown in FIG. 8. The contact 114 of the second change calculator 60 will be positioned generally between the first two conductive portions 354 and the last two conductive portions 354 of the circuit selector 112 or, more particularly, will be positioned such return position, as described that the contact 114 will contact two conductive portions 354 as the cam 106 is rotated to the starting position 356, the number of conductive portions 354 contacted by the contact 114 in returning to the starting position 356 determining the number of dollars change to be dispensed via the changer 66.

The change return position generally described above is also partially shown in FIG. 8, and, in this particular change position, electrical continuity between the second drive motor 100 and the power supply 22 via the mercury switch 130 and the switch 238 so that the second drive motor 100 will continue to drive the driver 102 and the cam 106 to return the cam 106 to the starting position 356 thereof. As the cam 106 is rotated in the counterclockwise direction 382 toward the starting position 356, the contact 114 will contactingly engage two of the conductive portions 354 on the circuit selector 112. Each time the contact 114 contacts one of the conductive portions 354, the solenoids in the changer 66 (the two 50-cent solenoids being diagrammatically shown in FIG. 8 and electrically connected so that the changer 66 dispenses one dollar in change when the solenoids are energized) are connected to the power supply 22 via the contacting engagement between the contact 114 and the particular conductive portion 354, the conductors 230, 264, 268, 252 and 254 and the mercury switch 132. In the operational example described above and shown in FIG. 8, the second change calculator 60 will dispense two dollars in change, and the first change calculator 52 will dispense 95,cents in change, the total change thus dispensed being $2.95, the correct change considering a purchase of $2.05 worth of the liquid.

After the cam 106 has been rotated to a position within an angular distance corresponding to the angular width 432 from the starting position 356, the switches 182 and 236 will be actuatingly engaged via the cam slot 372, thereby opening the switches 236 and 182. In the opened position of the switch 182, the switch 180 will again control the electrical bypass about the resistor 178 so that the rotational speed of the first drive motor 84 and the rotational speed of the second drive motor 100 is reduced, for reasons and in a manner as described above. The opening of the switch 236, more particularly, electrically connects the resistor 234 in the control circuit of the automatic change return apparatus to reduce the rotational speed of second drive motor 100.

It should be noted that the switches 206, 212, and 214 have been included in the control circuit and actuated by the cam 90 and the cam 106, to compensate for the initial movement of the cam 90 when the solenoid actuator 50 is first energized. For example, should the customer insert a S-dollar bill in the verifier 44, actuate the change return apparatus 10 to the pump position, and then dispense $1.05 worth of liquid via the liquid dispenser 12, in this event, the second change calculator 60 would indicate that three dollars in change should be returned to the customer; however, the first change calculator 52 will not have been rotated to the position wherein the contact 98 is in engagement with the first conductive portion 346. Thus, assuming the switches 212 and 214 were not included in the override network of the change return apparatus 10, the customer would receive only 3 dollars in change. The switches 212 and 214 cooperate to override switch 206, thereby postioning the first change calculator 52 to return cents in change, the customer thereby receiving the correct change $3.95.

It should also be noted that, in one form, the switches 172 and 174 are constructed to be a relay operated type of switch, and, in this form, a switch is supported on each of the switch supports 314 and 316, one switch energizing one relay to open and close a switch connected in the pump positioning network 28 in a manner similar to the switch 172, and one other switch energizing one other relay to open and close a switch connected in the pump positioning network 28 in a manner similar to the switch 174. This type of construction utilizing relay operated switches is particularly desirable where the switch is positioned in the automatic change return apparatus 10 such that the switch would require a relatively large amperage rating thereby increasing the size of the switch to such an extent that it would be difficult to support that particular switch on the switch support 314 or 316 for cooperation with the cam 90 or 106. It will be apparent to those skilled in the art, from the foregoing that, in one other form, any one of the switches 172, 212, 206, 210 or 180 supported on the switch support 314 and any one of the switches 258, 174, 238, 214, 236 or 182 supported on the switch support 316 can be of the relay operated type of switch, and connected in the automatic change return apparatus 10 in a manner similar to that described above with respect to the switches 172 and 174. However, in any event, the function and operational connection of the switches supported on the switch support 314 and 316 will remain essentially as described in detail before.

In utilizing the change return apparatus 10 in cooperation with particular gasoline pump type dispensers it may be desirable to modify the connection of the liquid price change network 192. For example, assuming the change return apparatus is to be utilized in cooperation with two separate liquid dispensers, one liquid dispenser for dispensing a relatively higher grade of gasoline with respect to the other liquid dispenser, two liquid price change networks can be connected in parallel and a switch disposed in each parallel network such that the closing of one of the switches operatively connects one of the liquid price change networks in the change return apparatus. In this form of the invention last-mentioned, each liquid price change network would be constructed similar to the liquid price change network 192; however, each liquid price change network would cooperate with one of the gasoline pump type dispensers since the pricing of the two grades of gasoline are usually different. In some other forms of particular gasoline pump type dispensers, a customer can turn a selector switch handle to position a single pump for dispensing various grades of gasoline. Utilizing the change return apparatus of the present invention in combination with a liquid dispenser of the type last-mentioned, a plurality of variable resistors can be connected such that one variable resistor is operatively connected in the change return apparatus for each grade of gasoline so selected each variable resistor functioning in a manner similar to that described before with respect to the variable resistor 196 when operatively connected.

Finally, the automatic change return apparatus 10 can be disconnected from the liquid dispenser 12 by opening the switch 82, thereby disconnecting the verifier 44 from the power supply 22; closing the switch to bypass the pump positioning network 28; and

opening the switch 202, thereby disconnecting the flow transmitter 30.

It will be apparent from the foregoing to those skilled in the art that automatic change return apparatus is constructed to be easily, efficiently and economically incorporated into existing liquid dispensing units, and that the change return apparatus 10 functions to accurately determine the change to be returned to the customer in such a manner that the price per unit of volume of the liquid being dispensed can be quickly and efficiently altered to adjust for price variations, and such that the apparatus can receive monetary inputs of various predetermined denominations, the change in each instance being the difference between the particular monetary input and the total price for the liquid dispensed by the customer.

Changes may be made in the construction and the operation of the various parts or the elements disclosed herein without departing from the spirit and the scope of the invention as defined in the following claims.

What is claimed is:

1. An automatic change return apparatus, comprising: changer means for dispensing predetermined amounts of change in energized positions thereof;

power supply means connected to the changer means, the power supply means energizing portions of the changer means when in electrical continuity therewith; circuit selector means having a plurality of conductive portions disposed thereon, the circuit selector means interposed between the power supply means and the changer means, each conductive portion connected to one portion of the changer means;

contact means interposed between the circuit selector means and the power supply means, a portion of the contact means movably contacting the circuit selector means;

means connected to the contact means for moving the contact means into contact with predetermined portions of the circuit selector means to establish electrical continuity between the power supply means and the changer means via the contact means and the conductive portions in contact with the contact means in an actuated position thereof, thereby energizing predetermined portions of the changer means to dispense a predetermined amount of change;

verifier means connected to the means for moving the contact means and to the power supply means for receiving a monetary input and actuating the means for moving the contact means upon verifying the genuineness of the monetary input;

a housing supporting the verifier means and the changer means;

air supply means connected to the housing supplying air thereto at a pressure level above atmospheric pressure to prevent air outside the housing from entering therein;

switch means interposed between the verifier means and the power supply means establishing electrical continuity therebetween in one position thereof; and

sensor means having a portion sensing the air being supplied via the air supply means and a portion connected to the switch means positioning the switch means to disconnect the power supply means from the verifier means upon sensing a malfunction of the air supply means. 2. An automatic change return apparatus, comprising:

changer means for dispensing predetermined amounts of change in energized positions thereof; power supply means connected to the changer means, the power supply means energizing portions of the changer means when in electrical continuity therewith; liquid dispenser means having a portion connected to the power supply means for dispensing liquid therethrough in one position thereof; means to sense the flow of liquid through the liquid dispenser and to provide an output flow signal responsive thereto; circuit selector means having a plurality of conductor portions disposed thereon and spaced thereabout generally near the outer periphery thereof, the circuit selector means interposed between the power supply means and the changer means, each conductive portion connected to one portion of the changer means; contact means interposed between the circuit selector means and the power supply means, a portion of the contact means movably contacting the circuit selector means; and means receiving the output flow signal and having a portion connected to the contact means for moving the contact means in response to the received flow signal into contact with predetermined conductive portions of the circuit selector means to establish electrical continuity between the power supply means and the changer means via the contact means and the conductive portions in contact with the contact means in an energized position thereof, thereby energizing predetermined portions of the changer means to dispense a predetermined amount of change, comprising: drive motor means receiving the output flow signal and having an output rotational speed responsive thereto; driver means connected to the drive motor means and being rotated thereby; cam means connected to the driver means and being rotated thereby, a portion of the cam means being connected to a portion of the contact means, a portion of the contact means ex tending between the cam means and the circuit selector means; shaft means rotatingly supporting the driver means and the cam means, the circuit selector means being secured in a stationary position about the shaft means and the cam means being interposed generally between the circuit selector means and the driver means; bushing means constructed of a conductive material connected to a portion of the cam means, the contact means being electrically connected to the bushing means; and conductive spacer means constructed of an electrically conductive material disposed about a portion of the shaft means generally between the cam means and the circuit selector means, a portion of the conductive spacer means engaging the bushing means to maintain a predetermined spacing between the cam means and the circuit selector means, the conductive spacer means and the bushing means maintaining an electrical path between the contact means and the power supply means in the stationary position of the circuit selector means and in a stationary position and in a rotating position of the cam means.

3. An automatic change return apparatus, comprising:

power supply means;

liquid dispenser means having a portion connected to the power supply means for dispensing liquid therethrough in one position thereof;

switch means interposed between the liquid dispenser means and the power supply means providing electrical continuity therebetween in the closed position thereof;

means to sense the flow of liquid through the liquid dispenser means and to provide an output flow signal responsive to the price of the liquid being dispensed;

first change calculator means having a portion receiving the output flow signal and another portion providing a predetermined number of output change signals responsive to the price of the liquid dispensed and a predetermined monetary input in an actuated position thereof, each change signal corresponding to a predetermined amount of change generally greater than one other change signal by a predetermined incremental amount, generally between zero and one predetermined monetary input, one portion of the first change calculator means connected to the switch means, for closing the switch means in an actuated position of the first change calculator means, the first change calculator means including:

a plurality of conductive portions;

contact means movably engaging the conductive portions in one position of the first change calculator means, the output change signal of the first change calculator means provided via the contacting engagement between the contact means and the conductive portions;

means for moving the contact means of the first change calculator means into contacting engagement with one of the conductive portions thereof in response to the liquid dispensed via the liquid dispenser means;

a second change calculator having a portion receiving the output flow signal and another portion providing a predetermined number of output change signals, each change signal responsive to the price of the liquid dispensed and one other predetermined monetary input in an actuated position thereof corresponding to a predetermined amount of change generally greater than one other change signal by a predetermined incremental amount, generally between zero and one other predetermined monetary input, the incremental amount of the second change calculator means being generally equal to the one predetermined monetary input of the first change calculator means, one other portion of g the second change calculator means connected to the switch means for closing the switch means in an actuated position of the second change calculator means, the second change calculator means including:

a plurality of conductive portions;

contact means movably engaging the conductive portions in one position of the second change calculator means, the output change signals of the second change calculator means provided via the contacting engagement between the contact means and the conductive portion;

means for moving the contact means in the second change calculator means into contacting engagement with a predetermined number of the conductive portions thereof responsive to the liquid dispensed via the liquid dispenser means;

means connected to the first and to the second change calculator means for receiving monetary inputs and actuating the first and the second calculator means in response thereto, the means for receiving the monetary inputs actuating the first change calculator means and the second change calculator means upon receiving the one other predetermined monetary input, the first change calculator means and the second change calculator means cooperating to provide change signals for dispensing change generally from zero to the one other predetermined monetary input in incremental amounts corresponding to the incremental amount of the first change calculator means, the

means receiving the monetary input including:

means for receiving the one predetermined monetary input and actuating the first change calculator means in response thereto; and

means for receiving the one other predetermined monetary input and actuating the second change calculator means in response thereto;

changer means receiving the output change signal and dispensing predetermined amounts of change in response thereto;

circuit breaker means interposed between the means to move the contact means and the first change calculator means and the power supply means and between the power supply means and the portion of the changer means connected to the first change calculator means to interrupt electrical continuity therebetween in an opened position thereof;

means to actuate the circuit breaker means when the changer means has dispensed the change therefrom;

override switch means to connect the first change calculator means to the power supply means after the changer means has dispensed the change, the first change calculator means being thereby returned to a starting position, the contacting engagement between the conductive portions and the contact means remaining disconnected from the changer means and the second change calculator means being thereby returned to a starting position and the contacting engagement between the contact means and a predetermined number of conductive portions providing a predetermined number of change signals therefrom.

4. An automatic change return apparatus, comprising:

changer means for dispensing predetermined amounts of change in energized positions thereof; power supply means connected to the changer means, the power supply means energizing portions 29 of the changer means when in electrical continuity therewith;

circuit selector means having a plurality of conductive portions disposed thereon and spaced thereabout generally near the outer periphery thereof, the circuit selector means interposed between the power supply means and the changer means, each conductive portion connected to one portion of the changer means;

contact means interposed between the circuit selector means and the power supply means, a portion of the contact means movably contacting the cir cuit selector means;

liquid dispenser means having a portion connected to the power supply means for dispensing liquid therethrough in one position thereof;

means to sense the flow of liquid through the liquid dispenser means and to provide an output flow sig nal responsive thereto;

means receiving the output flow signal and having a portion connected to the contact means for moving the contact means in response to the received flow signal into contact with predetermined conductive portions of the circuit selector means to establish electrical continuity between the power supply means and the changer means via the contact means and the conductive portions in contact with the contact means in an actuated position thereof,

thereby energizing portions of the changer means to dispense a predetermined amount of change,

comprising:

drive motor means receiving the output flow signal and having an output rotational speed responsive thereto;

driver means connected to the drive motor means and being rotated thereby;

circuit breaker means interposed between the changer means and the power supply means and between the liquid dispenser means and the power supply means to interrupt the electrical continuity therebetween in an opened position thereof;

means to actuate the circuit breaker means to the opened position when the changer means has dispensed the change therefrom;

override switch means to connect the drive motor means to the power supply means in one position thereof;

switch support means supporting the override switch means;

switch means supported on the switch support means interposed between the liquid dispenser means and the power supply means providing electrical continuity therebetween in the closed position thereof;

' cam means connected to the driver means and being rotated thereby, the cam means having a cam surface engaging and closing the override switch means and the switch means supported on the switch support means after the cam means has been rotated from a starting position a predetermined angular distance, and a cam slot means formed in a portion of the cam surface for disengaging and opening the override switch means and the switch means in the starting position of the cam means and during the rotation of the cam means from the starting position through a predetermined angular distance, the firstmentioned and the last-mentioned angular distance corresponding substantially to the angular width of the cam slot means;

means connected to the cam means for rotating the cam means a predetermined angular distance corresponding substantiallyto the angular width of the cam slot means in an energized position thereof; and

verifier means connected to the means for rotating the cam means a predetermined angular distance for receiving a monetary input and energizing said means upon verifying the genuineness ofthe monetaryinput, the liquid dispenser means being thereby disconnected from the power supply means until the verification of the monetary input and the drive motor means being thereby connected to the power supply means after the changer means has dispensed the change.

5. The apparatus of claim 4 wherein an extension arm is connected to a portion of the cam means; and wherein an extension arm is connected to a portion of the driver means, the driver extension arm engaging the cam extension arm after the driver means has been rotatedthrough an angular distance substantially corresponding to the angular width of the cam slot means to provide the connection between the cam means and the driver means, the driver means thereby being rotated 360 degrees while rotating the cam means through 360 degrees less an angular distance substantially corresponding to the angular width of the cam slot means.

6. An automatic change return apparatus, comprising:

power supply means;

liquid dispenser means having a portion connected to the power supply means dispensing liquid therethrough in one position thereof;

switch means interposed between the liquid dispenser means and the power supply means providing electrical continuity therebetween in a closed position thereof; means sensing the flow of liquid through the liquid dispenser means and providing an output flow signal responsive to the price of the liquid being dispensed; first change calculator means having a portion receiving the output flow signal and another portion providing an output change signal responsive to the price'of the liquid dispensed and a predetermined monetary input in an actuated position thereof, one other portion of the first change calculator means connected to the switch means closing the switch means in an actuated position of the first change calculator means, comprising: I circuit selector means having a. plurality of conductive portions disposed thereon, the circuit selector means interposed between the power supply means and the changer means, each conductive portion connected to one portion of the changer means; contact means interposed between the circuit selector means and the power supply means, a portion of the contact means mo vably contacting the circuit selector means;

drive motor means receiving the output flow signal and having an output rotational speed responsive thereto;

driver means connected to the drive motor means and being rotated thereby;

cam means connected to the driver means and being rotated thereby; and

contact means connected to the cam means and interposed between the circuit selector means and the power supply means, a portion of the contact means movably contacting predetermined conductive portions of the circuit selector means and moved into contacting engagement with predetermined conductive portions in response to the rotation of the cam means establishing electrical continuity between the power supply means and the changer means via the contact means and the conductive portions in contact with the contact means in an actuated position thereof, thereby energizing predetermined portions of the changer means to dispense a predetermined amount of change;

means connected to the first change calculator means receiving the monetary input and actuating the first change calculator in response thereto; and

" changer means receiving the output change signal and dispensing predetermined amounts of change in response thereto. 7. The apparatus of claim 6 wherein the first change calculator means provides a predetermined number of output change signals, each change signal corresponding to a predetermined amount of change generally greater than one other change signal by a predetermined incremental amount, generally between zero and one predetermined monetary input; and wherein the apparatus is defined further to include:

a second change calculator having a portion receiving the output flow signal and another portion providing a predetermined number of output change signals, each change signal responsive to the price of the liquid dispensed and one other predetermined monetary input in an actuated position thereof and corresponding to a predetermined amount of change generally greater than one other change signal by a predetermined incremental amount, generally between zero and the one other predetermined monetary input, the incremental amount of the second change calculator means being generally equal to the one predetermined monetary input of the first change calculator means, one other portion of the second change calculator means connected to the switch means for closing the switch means in an actuated position of the second change calculator means, comprising: circuitselector means having a plurality of conductive portions disposed thereon, the circuit selector means interposed between the power supply means and the changer means, each conductive portion connected to one portion of the changer means;

contact means interposed between the circuit selector means and the power supply means, a portion of the contact means movably contacting the circuit selector means;

drive motor means receiving the output flow signal and having an output rotational speed responsive thereto;

driver means connected to the drive motor means and being rotated thereby; cam means connected to the driver means and being rotated thereby; and contact means connected to the cam means and interposed between the circuit selector means and the power supply means, a portion of the contact means movably contacting predetermined conductive portions of the circuit selector means and moved into contacting engagement with predetermined conductive portions in response to the rotation of the cam means establishing electrical continuity between the power supply means and the changer means via the contact means and the conductive portions in contact with the contact means in an actuated position thereof, thereby energizing predetermined portions of the changer means to dispense a predetermined amount of change; and wherein the means for receiving the monetary input includes means for receiving the one predetermined monetary input and actuating the first change calculator means in response thereto, and means for receiving the one other predetermined monetary input and actuating the second change calculator means in response thereto.

8. The apparatus of claim 7 wherein the means for receiving the monetary input actuates the first change calculator means and the second change calculator means upon receiving the one other predetermined monetary input, the first change calculator means and the second change calculator means cooperating to provide change signals for dispensing change generally from zero to the one other predetermined monetary input in incremental amounts corresponding to the incremental amount of the first change calculator means.

9. An automatic change return apparatus, comprising:

changer means dispensing predetermined amounts of change in energized positions thereof;

power supply means connected to the changer means, the power supply means energizing portions of the changer means when in electrical continuity therewith;

liquid dispenser means having a portion connected to the power supply means dispensing liquid or the like therethrough in one position thereof;

means sensing the flow of liquid through the liquid dispenser means and providing an output flow signal responsive thereto;

circuit selector means having a plurality of conductive portions disposed thereon, the circuit selector means interposed between the power supply means and the changer means, each conductive portion connected to one portion of the changer means; contact means interposed between the circuit selector means and the power supply means, a portion of the contact means movably contacting the circuit selector means; and means receiving the output flow signal and having a portion connected to the contact means continuously moving the contact means at a rate of speed proportional to the received flow signal into contact with predetermined conductive portions of the circuit selector means to establish electrical continuity between the power supply means and the changer means via the contact means and the con- 

1. An automatic change return apparatus, comprising: changer means for dispensing predetermined amounts of change in energized positions thereof; power supply means connected to the changer means, the power supply means energizing portions of the changer means when in electrical continuity therewith; circuit selector means having a plurality of conductive portions disposed thereon, the circuit selector means interposed between the power supply means and the changer means, each conductive portion connected to one portion of the changer means; contact means interposed between the circuit selector means and the power supply means, a portion of the contact means movably contacting the circuit selector means; means connected to the contact means for moving the contact means into contact with predetermined portions of the circuit selector means to establish electrical continuity between the power supply means and the changer means via the contact means and the conductive portions in contact with the contact means in an actuated position thereof, thereby energizing predetermined portions of the changer means to dispense a predetermined amount of change; verifier means connected to the means for moving the contact means and to the power supply means for receiving a monetary input and actuating the means for moving the contact means upon verifying the genuineness of the monetary input; a housing supporting the verifier means and the changer means; air supply means connected to the housing supplying air thereto at a pressure level above atmospheric pressure to prevent air outside the housing from entering therein; switch means interposed between the verifier means and the power supply means establishing electrical continuity therebetween in one position thereof; and sensor means having a portion sensing the air being supplied via the air supply means and a portion connected to the switch means positioning the switch means to disconnect the power supply means from the verifier means upon sensing a malfunction of the air supply means.
 2. An automatic change return apparatus, comprising: changer means for dispensing predetermined amounts of change in energized positions thereof; power supply means connected to the changer means, the power supply means energizing portions of the changer means when in electrical continuity therewith; liquid dispenser means having a portion connected to the power supply means for dispensing liquid therethrough in one position thereof; means to sense the flow of liquid through the liquid dispenser and to provide an output flow signal responsive thereto; circuit selector means having a plurality of conductor portions disposed thereon and spaced thereabout generally near the outer periphery thereof, the circuit selector means interposed between the power supply means and the changer means, each conductive portion connected to one portion of the changer means; contact means interposed between the circuit selector means and the power supply means, a portion of the contact means movably contacting the circuit selector means; and means receiving the output flow signal and having a portion connected to the contact means for moving the contact means in response to the received flow signal into contact with predetermined conductive portions of the circuit selector means to establish electrical continuity between the power supply means and the changer means via the contact means and the conductive portions in contact with the contact means in an energized position thereof, thereby energizing predetermined portions of the changer means to dispense a predetermined amount of change, comprising: drive motor means receiving the output flow signal and having an output rotational speed responsive thereto; driver meAns connected to the drive motor means and being rotated thereby; cam means connected to the driver means and being rotated thereby, a portion of the cam means being connected to a portion of the contact means, a portion of the contact means extending between the cam means and the circuit selector means; shaft means rotatingly supporting the driver means and the cam means, the circuit selector means being secured in a stationary position about the shaft means and the cam means being interposed generally between the circuit selector means and the driver means; bushing means constructed of a conductive material connected to a portion of the cam means, the contact means being electrically connected to the bushing means; and conductive spacer means constructed of an electrically conductive material disposed about a portion of the shaft means generally between the cam means and the circuit selector means, a portion of the conductive spacer means engaging the bushing means to maintain a predetermined spacing between the cam means and the circuit selector means, the conductive spacer means and the bushing means maintaining an electrical path between the contact means and the power supply means in the stationary position of the circuit selector means and in a stationary position and in a rotating position of the cam means.
 3. An automatic change return apparatus, comprising: power supply means; liquid dispenser means having a portion connected to the power supply means for dispensing liquid therethrough in one position thereof; switch means interposed between the liquid dispenser means and the power supply means providing electrical continuity therebetween in the closed position thereof; means to sense the flow of liquid through the liquid dispenser means and to provide an output flow signal responsive to the price of the liquid being dispensed; first change calculator means having a portion receiving the output flow signal and another portion providing a predetermined number of output change signals responsive to the price of the liquid dispensed and a predetermined monetary input in an actuated position thereof, each change signal corresponding to a predetermined amount of change generally greater than one other change signal by a predetermined incremental amount, generally between zero and one predetermined monetary input, one portion of the first change calculator means connected to the switch means, for closing the switch means in an actuated position of the first change calculator means, the first change calculator means including: a plurality of conductive portions; contact means movably engaging the conductive portions in one position of the first change calculator means, the output change signal of the first change calculator means provided via the contacting engagement between the contact means and the conductive portions; means for moving the contact means of the first change calculator means into contacting engagement with one of the conductive portions thereof in response to the liquid dispensed via the liquid dispenser means; a second change calculator having a portion receiving the output flow signal and another portion providing a predetermined number of output change signals, each change signal responsive to the price of the liquid dispensed and one other predetermined monetary input in an actuated position thereof corresponding to a predetermined amount of change generally greater than one other change signal by a predetermined incremental amount, generally between zero and one other predetermined monetary input, the incremental amount of the second change calculator means being generally equal to the one predetermined monetary input of the first change calculator means, one other portion of the second change calculator means connected to the switch means for closing the switch means in an actuated position of the second change calculator means, the second change calculator means including: a Plurality of conductive portions; contact means movably engaging the conductive portions in one position of the second change calculator means, the output change signals of the second change calculator means provided via the contacting engagement between the contact means and the conductive portion; means for moving the contact means in the second change calculator means into contacting engagement with a predetermined number of the conductive portions thereof responsive to the liquid dispensed via the liquid dispenser means; means connected to the first and to the second change calculator means for receiving monetary inputs and actuating the first and the second calculator means in response thereto, the means for receiving the monetary inputs actuating the first change calculator means and the second change calculator means upon receiving the one other predetermined monetary input, the first change calculator means and the second change calculator means cooperating to provide change signals for dispensing change generally from zero to the one other predetermined monetary input in incremental amounts corresponding to the incremental amount of the first change calculator means, the means receiving the monetary input including: means for receiving the one predetermined monetary input and actuating the first change calculator means in response thereto; and means for receiving the one other predetermined monetary input and actuating the second change calculator means in response thereto; changer means receiving the output change signal and dispensing predetermined amounts of change in response thereto; circuit breaker means interposed between the means to move the contact means and the first change calculator means and the power supply means and between the power supply means and the portion of the changer means connected to the first change calculator means to interrupt electrical continuity therebetween in an opened position thereof; means to actuate the circuit breaker means when the changer means has dispensed the change therefrom; override switch means to connect the first change calculator means to the power supply means after the changer means has dispensed the change, the first change calculator means being thereby returned to a starting position, the contacting engagement between the conductive portions and the contact means remaining disconnected from the changer means and the second change calculator means being thereby returned to a starting position and the contacting engagement between the contact means and a predetermined number of conductive portions providing a predetermined number of change signals therefrom.
 4. An automatic change return apparatus, comprising: changer means for dispensing predetermined amounts of change in energized positions thereof; power supply means connected to the changer means, the power supply means energizing portions of the changer means when in electrical continuity therewith; circuit selector means having a plurality of conductive portions disposed thereon and spaced thereabout generally near the outer periphery thereof, the circuit selector means interposed between the power supply means and the changer means, each conductive portion connected to one portion of the changer means; contact means interposed between the circuit selector means and the power supply means, a portion of the contact means movably contacting the circuit selector means; liquid dispenser means having a portion connected to the power supply means for dispensing liquid therethrough in one position thereof; means to sense the flow of liquid through the liquid dispenser means and to provide an output flow signal responsive thereto; means receiving the output flow signal and having a portion connected to the contact means for moving the contact means in response to the received flow signal into contact with predetermined conductive portions of the circuit selector means to establish Electrical continuity between the power supply means and the changer means via the contact means and the conductive portions in contact with the contact means in an actuated position thereof, thereby energizing portions of the changer means to dispense a predetermined amount of change, comprising: drive motor means receiving the output flow signal and having an output rotational speed responsive thereto; driver means connected to the drive motor means and being rotated thereby; circuit breaker means interposed between the changer means and the power supply means and between the liquid dispenser means and the power supply means to interrupt the electrical continuity therebetween in an opened position thereof; means to actuate the circuit breaker means to the opened position when the changer means has dispensed the change therefrom; override switch means to connect the drive motor means to the power supply means in one position thereof; switch support means supporting the override switch means; switch means supported on the switch support means interposed between the liquid dispenser means and the power supply means providing electrical continuity therebetween in the closed position thereof; cam means connected to the driver means and being rotated thereby, the cam means having a cam surface engaging and closing the override switch means and the switch means supported on the switch support means after the cam means has been rotated from a starting position a predetermined angular distance, and a cam slot means formed in a portion of the cam surface for disengaging and opening the override switch means and the switch means in the starting position of the cam means and during the rotation of the cam means from the starting position through a predetermined angular distance, the first-mentioned and the last-mentioned angular distance corresponding substantially to the angular width of the cam slot means; means connected to the cam means for rotating the cam means a predetermined angular distance corresponding substantially to the angular width of the cam slot means in an energized position thereof; and verifier means connected to the means for rotating the cam means a predetermined angular distance for receiving a monetary input and energizing said means upon verifying the genuineness of the monetary input, the liquid dispenser means being thereby disconnected from the power supply means until the verification of the monetary input and the drive motor means being thereby connected to the power supply means after the changer means has dispensed the change.
 5. The apparatus of claim 4 wherein an extension arm is connected to a portion of the cam means; and wherein an extension arm is connected to a portion of the driver means, the driver extension arm engaging the cam extension arm after the driver means has been rotated through an angular distance substantially corresponding to the angular width of the cam slot means to provide the connection between the cam means and the driver means, the driver means thereby being rotated 360 degrees while rotating the cam means through 360 degrees less an angular distance substantially corresponding to the angular width of the cam slot means.
 6. An automatic change return apparatus, comprising: power supply means; liquid dispenser means having a portion connected to the power supply means dispensing liquid therethrough in one position thereof; switch means interposed between the liquid dispenser means and the power supply means providing electrical continuity therebetween in a closed position thereof; means sensing the flow of liquid through the liquid dispenser means and providing an output flow signal responsive to the price of the liquid being dispensed; first change calculator means having a portion receiving the output flow signal and another portion providing an output change signal responsive to the price of the liquid dispensed and a predEtermined monetary input in an actuated position thereof, one other portion of the first change calculator means connected to the switch means closing the switch means in an actuated position of the first change calculator means, comprising: circuit selector means having a plurality of conductive portions disposed thereon, the circuit selector means interposed between the power supply means and the changer means, each conductive portion connected to one portion of the changer means; contact means interposed between the circuit selector means and the power supply means, a portion of the contact means movably contacting the circuit selector means; drive motor means receiving the output flow signal and having an output rotational speed responsive thereto; driver means connected to the drive motor means and being rotated thereby; cam means connected to the driver means and being rotated thereby; and contact means connected to the cam means and interposed between the circuit selector means and the power supply means, a portion of the contact means movably contacting predetermined conductive portions of the circuit selector means and moved into contacting engagement with predetermined conductive portions in response to the rotation of the cam means establishing electrical continuity between the power supply means and the changer means via the contact means and the conductive portions in contact with the contact means in an actuated position thereof, thereby energizing predetermined portions of the changer means to dispense a predetermined amount of change; means connected to the first change calculator means receiving the monetary input and actuating the first change calculator in response thereto; and changer means receiving the output change signal and dispensing predetermined amounts of change in response thereto.
 7. The apparatus of claim 6 wherein the first change calculator means provides a predetermined number of output change signals, each change signal corresponding to a predetermined amount of change generally greater than one other change signal by a predetermined incremental amount, generally between zero and one predetermined monetary input; and wherein the apparatus is defined further to include: a second change calculator having a portion receiving the output flow signal and another portion providing a predetermined number of output change signals, each change signal responsive to the price of the liquid dispensed and one other predetermined monetary input in an actuated position thereof and corresponding to a predetermined amount of change generally greater than one other change signal by a predetermined incremental amount, generally between zero and the one other predetermined monetary input, the incremental amount of the second change calculator means being generally equal to the one predetermined monetary input of the first change calculator means, one other portion of the second change calculator means connected to the switch means for closing the switch means in an actuated position of the second change calculator means, comprising: circuit selector means having a plurality of conductive portions disposed thereon, the circuit selector means interposed between the power supply means and the changer means, each conductive portion connected to one portion of the changer means; contact means interposed between the circuit selector means and the power supply means, a portion of the contact means movably contacting the circuit selector means; drive motor means receiving the output flow signal and having an output rotational speed responsive thereto; driver means connected to the drive motor means and being rotated thereby; cam means connected to the driver means and being rotated thereby; and contact means connected to the cam means and interposed between the circuit selector means and the power supply means, a portion of the contact means movably contacting predetermined conductive portions of the circuit selector means and moved into contacting engagement with predetermined conductive portions in response to the rotation of the cam means establishing electrical continuity between the power supply means and the changer means via the contact means and the conductive portions in contact with the contact means in an actuated position thereof, thereby energizing predetermined portions of the changer means to dispense a predetermined amount of change; and wherein the means for receiving the monetary input includes means for receiving the one predetermined monetary input and actuating the first change calculator means in response thereto, and means for receiving the one other predetermined monetary input and actuating the second change calculator means in response thereto.
 8. The apparatus of claim 7 wherein the means for receiving the monetary input actuates the first change calculator means and the second change calculator means upon receiving the one other predetermined monetary input, the first change calculator means and the second change calculator means cooperating to provide change signals for dispensing change generally from zero to the one other predetermined monetary input in incremental amounts corresponding to the incremental amount of the first change calculator means.
 9. An automatic change return apparatus, comprising: changer means dispensing predetermined amounts of change in energized positions thereof; power supply means connected to the changer means, the power supply means energizing portions of the changer means when in electrical continuity therewith; liquid dispenser means having a portion connected to the power supply means dispensing liquid or the like therethrough in one position thereof; means sensing the flow of liquid through the liquid dispenser means and providing an output flow signal responsive thereto; circuit selector means having a plurality of conductive portions disposed thereon, the circuit selector means interposed between the power supply means and the changer means, each conductive portion connected to one portion of the changer means; contact means interposed between the circuit selector means and the power supply means, a portion of the contact means movably contacting the circuit selector means; and means receiving the output flow signal and having a portion connected to the contact means continuously moving the contact means at a rate of speed proportional to the received flow signal into contact with predetermined conductive portions of the circuit selector means to establish electrical continuity between the power supply means and the changer means via the contact means and the conductive portions in contact with the contact means in an actuated position thereof, thereby energizing predetermined portions of the changer means to dispense a predetermined amount of change.
 10. The apparatus of claim 9 defined further to include: verifier means connected to the means for moving the contact means and to the power supply means for receiving a monetary input and actuating the means for moving the contact means upon verifying the genuineness of the monetary input.
 11. The apparatus of claim 9 wherein the means for moving the contact means includes: drive motor means receiving the output flow signal and having an output rotational speed responsive thereto; driver means connected to the drive motor means and being rotated thereby; and cam means connected to the driver means and being rotated thereby; and wherein the contact means is defined further as being connected to a portion of the cam means; and wherein the conductive portions of the circuit selector means are spaced thereabout generally near the outer periphery thereof.
 12. The apparatus of claim 11 defined further to include: switch means connected to a portion of the liquid dispenser means having a pump position and a change position and connecting the drive motor means to thE power supply means in a change position and connecting the drive motor means to the power supply via the means to sense the flow of liquid in a pump position; and wherein the liquid dispenser means includes: means to actuate the switch means to a pump position in one position of the liquid dispenser means and to a change position in one other position of the liquid dispenser means.
 13. The apparatus of claim 11 defined further to include: liquid price change means interposed between the drive motor means and the means to sense the flow of liquid to control the flow signal to the driver motor means, the flow signal being responsive to rate of the flow through the liquid dispenser means and the price of the liquid per unit volume, the liquid price change having a portion thereof adjustable for controllingly setting the flow signal to be responsive to a plurality of predetermined prices of the liquid per unit volume.
 14. The apparatus of claim 11 defined further to include: shaft means; and wherein the driver means and the cam means are each rotatingly supported on the shaft means; and the circuit selector means is secured in a stationary position about the shaft means, the cam means being interposed generally between the circuit selector means and the driver means.
 15. The apparatus of claim 14 wherein each of the conductive portions of the circuit selector means is connected to a predetermined portion of the changer means for energizing the changer means to dispense change in amounts from zero to one dollar in 5-cent increments; and wherein the drive motor means drivingly rotates the cam means via the driver means to move the contact means generally from contacting engagement with one conductive portion to contacting engagement with one other conductive portion as each 5-cent portion of liquid is dispensed via the liquid dispenser means.
 16. The apparatus of claim 11 defined further to include: circuit breaker means interposed between the changer means and the power supply means and between the liquid dispenser means and the power supply means to interrupt the electrical continuity therebetween in an opened position thereof; means to actuate the circuit breaker means to the opened position when the changer means has dispensed the change therefrom; and override switch means to connect the drive motor means to the power supply means to return the driver means and the cam means to the starting positions thereof after the changer means has dispensed the change.
 17. The apparatus of claim 16 wherein each of the conductive portions of the circuit selector means is connected to a predetermined portion of the changer means for energizing the changer means to dispense one predetermined amount of change; and wherein the drive motor means drivingly rotates the cam means via the driver means to move the contact means to a position wherein the contact means contactingly engages a predetermined number of the conductive portions as the cam means returns to the starting position thereof. 